"""Integration tests for notification preferences, unsubscribe, and digest task.

Tests:
  - GET/PUT notification preferences (auth required)
  - PUT with invalid digest_frequency value → 422
  - GET/PUT without auth → 401
  - Unsubscribe with valid token
  - Unsubscribe with expired token
  - Unsubscribe with tampered token
  - Digest task happy path (mocked SMTP)
  - Digest task skips when no new content
  - Digest task no-op when SMTP unconfigured

Uses a standalone ASGI test client to avoid importing the full app
(which may reference routers not present in the running container image).
"""

from __future__ import annotations

import os
import pathlib
import sys
import time
import uuid
from datetime import datetime, timezone
from unittest.mock import MagicMock, patch

import jwt
import pytest
import pytest_asyncio
from httpx import ASGITransport, AsyncClient
from sqlalchemy import select, update as sa_update
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
from sqlalchemy.orm import Session, sessionmaker
from sqlalchemy.pool import NullPool

# Ensure backend/ on path
sys.path.insert(0, str(pathlib.Path(__file__).resolve().parent.parent))

from database import Base, get_session  # noqa: E402
from models import (  # noqa: E402
    Creator,
    CreatorFollow,
    EmailDigestLog,
    InviteCode,
    Post,
    User,
)

TEST_DATABASE_URL = os.getenv(
    "TEST_DATABASE_URL",
    "postgresql+asyncpg://chrysopedia:changeme@localhost:5433/chrysopedia_test",
)
TEST_DATABASE_URL_SYNC = TEST_DATABASE_URL.replace(
    "postgresql+asyncpg://", "postgresql+psycopg2://"
)

_SECRET = "changeme-generate-a-real-secret"


# ── Standalone test app ──────────────────────────────────────────────────────

def _make_test_app():
    """Build a minimal FastAPI app with only the notifications router + auth."""
    from fastapi import FastAPI
    from routers.notifications import router as notif_router
    from routers.auth import router as auth_router

    test_app = FastAPI()
    test_app.include_router(auth_router, prefix="/api/v1")
    test_app.include_router(notif_router, prefix="/api/v1")
    return test_app


# ── Fixtures ─────────────────────────────────────────────────────────────────

@pytest_asyncio.fixture()
async def db_engine():
    engine = create_async_engine(TEST_DATABASE_URL, echo=False, poolclass=NullPool)
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
        await conn.run_sync(Base.metadata.create_all)
    yield engine
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
    await engine.dispose()


@pytest_asyncio.fixture()
async def sync_engine_fix(db_engine):
    """Sync engine pointing at same test DB (tables created by db_engine)."""
    from sqlalchemy import create_engine
    engine = create_engine(TEST_DATABASE_URL_SYNC, echo=False, poolclass=NullPool)
    yield engine
    engine.dispose()


@pytest_asyncio.fixture()
async def client(db_engine, tmp_path):
    test_app = _make_test_app()
    session_factory = async_sessionmaker(
        db_engine, class_=AsyncSession, expire_on_commit=False
    )

    async def _override_get_session():
        async with session_factory() as session:
            yield session

    test_app.dependency_overrides[get_session] = _override_get_session

    # Clear settings cache so tests get fresh defaults
    from config import get_settings
    get_settings.cache_clear()

    transport = ASGITransport(app=test_app)
    async with AsyncClient(transport=transport, base_url="http://testserver") as ac:
        yield ac

    test_app.dependency_overrides.clear()
    get_settings.cache_clear()


@pytest_asyncio.fixture()
async def invite_code(db_engine):
    factory = async_sessionmaker(db_engine, class_=AsyncSession, expire_on_commit=False)
    async with factory() as session:
        code = InviteCode(code="NOTIF-TEST-2026", uses_remaining=10)
        session.add(code)
        await session.commit()
    return "NOTIF-TEST-2026"


@pytest_asyncio.fixture()
async def registered_user(client, invite_code):
    resp = await client.post("/api/v1/auth/register", json={
        "email": "notiftest@chrysopedia.com",
        "password": "testpass123",
        "display_name": "Notif Test User",
        "invite_code": invite_code,
    })
    assert resp.status_code == 201, f"Register failed: {resp.text}"
    return resp.json()


@pytest_asyncio.fixture()
async def auth_headers(client, registered_user):
    resp = await client.post("/api/v1/auth/login", json={
        "email": "notiftest@chrysopedia.com",
        "password": "testpass123",
    })
    assert resp.status_code == 200, f"Login failed: {resp.text}"
    token = resp.json()["access_token"]
    return {"Authorization": f"Bearer {token}"}


# ── Helpers ──────────────────────────────────────────────────────────────────

def _make_unsubscribe_token(user_id: str, secret: str = _SECRET, iat: float | None = None) -> str:
    payload = {
        "sub": user_id,
        "purpose": "unsubscribe",
        "iat": iat or datetime.now(timezone.utc).timestamp(),
    }
    return jwt.encode(payload, secret, algorithm="HS256")


# ── Preference endpoint tests ───────────────────────────────────────────────


@pytest.mark.asyncio
async def test_get_preferences_requires_auth(client):
    resp = await client.get("/api/v1/notifications/preferences")
    assert resp.status_code == 401


@pytest.mark.asyncio
async def test_put_preferences_requires_auth(client):
    resp = await client.put(
        "/api/v1/notifications/preferences",
        json={"email_digests": False},
    )
    assert resp.status_code == 401


@pytest.mark.asyncio
async def test_get_preferences_defaults(client, auth_headers):
    resp = await client.get("/api/v1/notifications/preferences", headers=auth_headers)
    assert resp.status_code == 200
    data = resp.json()
    assert data["email_digests"] is True
    assert data["digest_frequency"] == "daily"


@pytest.mark.asyncio
async def test_put_preferences_update_digests(client, auth_headers):
    resp = await client.put(
        "/api/v1/notifications/preferences",
        json={"email_digests": False},
        headers=auth_headers,
    )
    assert resp.status_code == 200
    assert resp.json()["email_digests"] is False
    assert resp.json()["digest_frequency"] == "daily"

    # Verify persistence
    resp2 = await client.get("/api/v1/notifications/preferences", headers=auth_headers)
    assert resp2.json()["email_digests"] is False


@pytest.mark.asyncio
async def test_put_preferences_update_frequency(client, auth_headers):
    resp = await client.put(
        "/api/v1/notifications/preferences",
        json={"digest_frequency": "weekly"},
        headers=auth_headers,
    )
    assert resp.status_code == 200
    assert resp.json()["digest_frequency"] == "weekly"


@pytest.mark.asyncio
async def test_put_preferences_invalid_frequency(client, auth_headers):
    resp = await client.put(
        "/api/v1/notifications/preferences",
        json={"digest_frequency": "monthly"},
        headers=auth_headers,
    )
    assert resp.status_code == 422


# ── Unsubscribe endpoint tests ──────────────────────────────────────────────


@pytest.mark.asyncio
async def test_unsubscribe_valid_token(client, auth_headers, db_engine):
    factory = async_sessionmaker(db_engine, class_=AsyncSession, expire_on_commit=False)
    async with factory() as session:
        result = await session.execute(select(User).limit(1))
        user = result.scalar_one()
        user_id = str(user.id)

    token = _make_unsubscribe_token(user_id)
    resp = await client.get(f"/api/v1/notifications/unsubscribe?token={token}")
    assert resp.status_code == 200
    assert "Unsubscribed" in resp.text

    # Verify preferences updated
    async with factory() as session:
        result = await session.execute(select(User).where(User.id == user.id))
        updated = result.scalar_one()
        assert updated.notification_preferences.get("email_digests") is False


@pytest.mark.asyncio
async def test_unsubscribe_expired_token(client, auth_headers, db_engine):
    factory = async_sessionmaker(db_engine, class_=AsyncSession, expire_on_commit=False)
    async with factory() as session:
        result = await session.execute(select(User).limit(1))
        user = result.scalar_one()

    expired_iat = time.time() - (31 * 24 * 3600)
    token = _make_unsubscribe_token(str(user.id), iat=expired_iat)
    resp = await client.get(f"/api/v1/notifications/unsubscribe?token={token}")
    assert resp.status_code == 400


@pytest.mark.asyncio
async def test_unsubscribe_tampered_token(client):
    token = _make_unsubscribe_token(str(uuid.uuid4()), secret="wrong-secret")
    resp = await client.get(f"/api/v1/notifications/unsubscribe?token={token}")
    assert resp.status_code == 400


# ── Digest task tests ────────────────────────────────────────────────────────


@pytest.mark.asyncio
async def test_digest_task_smtp_unconfigured():
    """Digest task gracefully skips when SMTP is not configured."""
    from tasks.notifications import send_digest_emails
    with patch("tasks.notifications.is_smtp_configured", return_value=False):
        result = send_digest_emails()
    assert result["skipped"] is True
    assert result["reason"] == "smtp_not_configured"


@pytest.mark.asyncio
async def test_digest_task_happy_path(client, auth_headers, db_engine, sync_engine_fix):
    """Full digest: user follows creator, new post exists, SMTP mocked → email sent."""
    sync_factory = sessionmaker(bind=sync_engine_fix)

    factory = async_sessionmaker(db_engine, class_=AsyncSession, expire_on_commit=False)
    async with factory() as session:
        result = await session.execute(select(User).limit(1))
        user = result.scalar_one()
        user_id = user.id
        user_email = user.email

        # Ensure digests enabled
        await session.execute(
            sa_update(User).where(User.id == user_id).values(
                notification_preferences={"email_digests": True, "digest_frequency": "daily"}
            )
        )
        await session.commit()

        # Create creator
        creator = Creator(
            name="DigestTestCreator",
            slug="digest-test-creator",
            folder_name="DigestTestCreator",
        )
        session.add(creator)
        await session.flush()
        creator_id = creator.id

        # Follow
        follow = CreatorFollow(user_id=user_id, creator_id=creator_id)
        session.add(follow)

        # Published post
        post = Post(
            creator_id=creator_id,
            title="Test Digest Post",
            body_json={"blocks": [{"type": "paragraph", "content": "Some content"}]},
            is_published=True,
        )
        session.add(post)
        await session.commit()

    # Mock SMTP and sync session
    mock_send = MagicMock(return_value=True)

    with (
        patch("tasks.notifications.is_smtp_configured", return_value=True),
        patch("tasks.notifications.send_email", mock_send),
        patch("tasks.notifications._get_sync_session") as mock_session_fn,
    ):
        sync_session = sync_factory()
        mock_session_fn.return_value = sync_session

        from tasks.notifications import send_digest_emails
        result = send_digest_emails()

    assert result["sent"] >= 1
    assert mock_send.called
    call_args = mock_send.call_args
    assert user_email in str(call_args)

    # Verify EmailDigestLog
    verify_session = sync_factory()
    try:
        logs = verify_session.execute(
            select(EmailDigestLog).where(EmailDigestLog.user_id == user_id)
        ).scalars().all()
        assert len(logs) >= 1
    finally:
        verify_session.close()


@pytest.mark.asyncio
async def test_digest_task_no_new_content(client, auth_headers, db_engine, sync_engine_fix):
    """Digest task skips users with no new content."""
    sync_factory = sessionmaker(bind=sync_engine_fix)

    factory = async_sessionmaker(db_engine, class_=AsyncSession, expire_on_commit=False)
    async with factory() as session:
        result = await session.execute(select(User).limit(1))
        user = result.scalar_one()
        user_id = user.id

        # Digests enabled but no follows
        await session.execute(
            sa_update(User).where(User.id == user_id).values(
                notification_preferences={"email_digests": True, "digest_frequency": "daily"}
            )
        )
        await session.commit()

    mock_send = MagicMock(return_value=True)

    with (
        patch("tasks.notifications.is_smtp_configured", return_value=True),
        patch("tasks.notifications.send_email", mock_send),
        patch("tasks.notifications._get_sync_session") as mock_session_fn,
    ):
        sync_session = sync_factory()
        mock_session_fn.return_value = sync_session

        from tasks.notifications import send_digest_emails
        result = send_digest_emails()

    assert result["sent"] == 0
    assert result["skipped"] >= 1
    assert not mock_send.called